How to Change the Hashing/Algorythym/Encryption of WordPress?

This is the Code but i dont know how to make my own structure,check for hash please bear with me. and this is the way of encryption i want to replace.
md5($password.”Mgi4xhFCVuyWYSpF4EaXXXXXXXXXXXXXXXXXYgsS”);

in function.php i will put this

if ( !function_exists(‘wp_hash_password’) ){
function wp_hash_password($password) {
//apply your own hashing structure here
return $password;
}
}

if ( !function_exists(‘wp_check_password’) ){
function wp_check_password($password, $hash, $user_id = ”) {
//check for your hash match
return apply_filters(‘check_password’, $check, $password, $hash, $user_id);
}
}

The main reason is my Boss want to link the other webistes account in my wordpress website by using API. but they are different encrpytion its hard for me to do the thing.
Thank you so much.

[ Bumps deleted, stop bumping ]